5.5.2 Outlook
There is increasing evidence that global N cycle altered by human activity is
negatively affecting human and ecosystem health. China is facing the biggest
challenge raised by the great N loss and its connection to food production and
environmental security. The pressure is that China must continue to enhance crop
yields, to maintain a still-growing and ever-wealthier population and to offset the
large imports of animal feed that it considers to be a threat to food security. At the
same time, China needs to make a great effort to reduce the environmental and health
consequences of excessive Nr far below their current levels. Trading off human
health and environment for yields is no longer advisable and feasible since the
corresponding costs are already excessive and unacceptable.
Fortunately, a set of pathways are still available to reduce the pressure and costs
of anthropogenic Nr pollution in China. One such pathway is diet manipulation, that
is, shifting from meat-rich diet to a more “balanced diet”, which recommends that
people eat more cereals, vegetables, and fruit. A second pathway is increasing the
NUE of food production systems to match those in the United States and Europe by
improving livestock breeding and feed mixtures. A third pathway is to make full use
of animal waste and crop residues. Great improvement potential exists due to the fact
that cropland in China is poorly coupled to the livestock and human subsystems; the
overall N recycling ratios of livestock excreta and human waste were only 45% and
24%, respectively, in 2010s. Based on our previous scenario analysis (Gu et al.
2015), combination of these three pathways could greatly reduce Nr creation and
thereby reduce associated health and environmental damages while at the same time
enhancing food security. It is achievable that under effective governance policy,
China would reduce Nr, increase food production, and improve human health and
the environment under. However, a lot of further work remains to be done to explore
political, social, and economic means to guarantee a safe and green future for
China’s N use.
References
Chen D, Li Y, Grace P et al (2008) N 2 O emissions from agricultural lands: a synthesis of simulation
approaches. Plant Soil 309(1/2):169–189. https://doi.org/10.1007/s11104-008-9634-0
Chen X, Cui Z, Fan M et al (2014) Producing more grain with lower environmental costs. Nature
514(7523):486–489. https://doi.org/10.1038/nature13609
Cui S, Shi Y, Groffman PM et al (2013) Centennial-scale analysis of the creation and fate of reactive
nitrogen in China (1910–2010). Proc Natl Acad Sci U S A 110(6):2052–2057
De Vries W, Leip A, Reinds GJ et al (2011) Geographical variation in terrestrial nitrogen budgets
across Europe. In: Sutton M, Howard C, Erisman JW et al (eds) The European nitrogen
assessment. Cambridge University Press, Cambridge, pp 317–344
EDGAR (2010) Emissions Database for Global Atmospheric Research (EDGAR v4.3.1).
Available. URL. http://edgar.jrc.ec.europa.eu/overview.php?v¼431. Accessed 6 July 2016
106
B. Gu and X. Zhang
There is increasing evidence that global N cycle altered by human activity is
negatively affecting human and ecosystem health. China is facing the biggest
challenge raised by the great N loss and its connection to food production and
environmental security. The pressure is that China must continue to enhance crop
yields, to maintain a still-growing and ever-wealthier population and to offset the
large imports of animal feed that it considers to be a threat to food security. At the
same time, China needs to make a great effort to reduce the environmental and health
consequences of excessive Nr far below their current levels. Trading off human
health and environment for yields is no longer advisable and feasible since the
corresponding costs are already excessive and unacceptable.
Fortunately, a set of pathways are still available to reduce the pressure and costs
of anthropogenic Nr pollution in China. One such pathway is diet manipulation, that
is, shifting from meat-rich diet to a more “balanced diet”, which recommends that
people eat more cereals, vegetables, and fruit. A second pathway is increasing the
NUE of food production systems to match those in the United States and Europe by
improving livestock breeding and feed mixtures. A third pathway is to make full use
of animal waste and crop residues. Great improvement potential exists due to the fact
that cropland in China is poorly coupled to the livestock and human subsystems; the
overall N recycling ratios of livestock excreta and human waste were only 45% and
24%, respectively, in 2010s. Based on our previous scenario analysis (Gu et al.
2015), combination of these three pathways could greatly reduce Nr creation and
thereby reduce associated health and environmental damages while at the same time
enhancing food security. It is achievable that under effective governance policy,
China would reduce Nr, increase food production, and improve human health and
the environment under. However, a lot of further work remains to be done to explore
political, social, and economic means to guarantee a safe and green future for
China’s N use.
References
Chen D, Li Y, Grace P et al (2008) N 2 O emissions from agricultural lands: a synthesis of simulation
approaches. Plant Soil 309(1/2):169–189. https://doi.org/10.1007/s11104-008-9634-0
Chen X, Cui Z, Fan M et al (2014) Producing more grain with lower environmental costs. Nature
514(7523):486–489. https://doi.org/10.1038/nature13609
Cui S, Shi Y, Groffman PM et al (2013) Centennial-scale analysis of the creation and fate of reactive
nitrogen in China (1910–2010). Proc Natl Acad Sci U S A 110(6):2052–2057
De Vries W, Leip A, Reinds GJ et al (2011) Geographical variation in terrestrial nitrogen budgets
across Europe. In: Sutton M, Howard C, Erisman JW et al (eds) The European nitrogen
assessment. Cambridge University Press, Cambridge, pp 317–344
EDGAR (2010) Emissions Database for Global Atmospheric Research (EDGAR v4.3.1).
Available. URL. http://edgar.jrc.ec.europa.eu/overview.php?v¼431. Accessed 6 July 2016
106
B. Gu and X. Zhang